20974091 has 4 divisors (see below), whose sum is σ = 21886032. Its totient is φ = 20062152.

The previous prime is 20974049. The next prime is 20974111. The reversal of 20974091 is 19047902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20974091 - 2¹⁴ = 20957707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20974021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 455936 + ... + 455981.

It is an arithmetic number, because the mean of its divisors is an integer number (5471508).

Almost surely, 2^20974091 is an apocalyptic number.

20974091 is a deficient number, since it is larger than the sum of its proper divisors (911941).

20974091 is an equidigital number, since it uses as much as digits as its factorization.

20974091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911940.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20974091 is about 4579.7479188270. The cubic root of 20974091 is about 275.7789090929.

The spelling of 20974091 in words is "twenty million, nine hundred seventy-four thousand, ninety-one".